#459 - Fix iteration for genomics API which only has 1 item per page

spec/google/apis/core/service_spec.rb

@@ -248,9 +248,9 @@ EOF
     context 'with fetch_all' do
       let(:responses) do
         data = {}
-        data[nil] = OpenStruct.new(next_page_token: 'p1', items: ['a', 'b', 'c'], alt_items: [1, 2 , 3])
-        data['p1'] = OpenStruct.new(next_page_token: 'p2', items: ['d', 'e', 'f'], alt_items: [4, 5, 6])
-        data['p2'] = OpenStruct.new(next_page_token: nil, items: ['g', 'h', 'i'], alt_items: [7,8, 9])
+        data[nil] = OpenStruct.new(next_page_token: 'p1', items: ['a', 'b', 'c'], alt_items: [1, 2 , 3], singular: 'foo')
+        data['p1'] = OpenStruct.new(next_page_token: 'p2', items: ['d', 'e', 'f'], alt_items: [4, 5, 6], singular: 'bar')
+        data['p2'] = OpenStruct.new(next_page_token: nil, items: ['g', 'h', 'i'], alt_items: [7,8, 9], singular: 'baz')
         data
       end
 
@@ -274,6 +274,10 @@ EOF
         expect(service.fetch_all(items: :alt_items) { |token| responses[token] } ).to contain_exactly(1, 2, 3, 4, 5, 6, 7, 8, 9)
       end
 
+      it 'should allow iterating over singular items' do
+        expect(service.fetch_all(items: :singular) { |token| responses[token] } ).to contain_exactly('foo', 'bar', 'baz')
+      end
+
       it 'should allow limiting the number of items to fetch' do
         expect(service.fetch_all(max: 5) { |token| responses[token] } ).to contain_exactly('a', 'b', 'c', 'd', 'e')
       end